Practical and Operational Genetic Sexing Systems Based on Classical Genetic Approaches in Fruit Flies, an Example for other Species Amenable to Large-Scale Rearing for the Sterile Insect Technique

Abstract

Through genetic and molecular manipulations, strains can be developed that are more suitable for the sterile insect technique (SIT). In this chapter the development of genetic sexing strains (GSSs) using classical genetic approaches is described, while the development of GSSs using molecular approaches is discussed by Häcker et al. (this volume). GSSs increase the effectiveness of area-wide integrated pest management (AW-IPM) programmes that use the SIT by enabling the large-scale production and release of only sterile males, and generally increasing sterile-male effectiveness when competing for wild females in the absence of sterile females. For species that transmit disease, the removal of females is mandatory. GSSs have been developed for several species, including Tephritidae and mosquitoes. For the Mediterranean fruit fly Ceratitis capitata (Wiedemann) and the Mexican fruit fly Anastrepha ludens (Loew), genetic sexing systems have been developed, and they have been shown to be stable enough at large-scale mass-rearing levels to be used in operational programmes for extended periods of time. In this chapter, the basic principle of translocation-based sexing strains is described, and Mediterranean fruit fly and Mexican fruit fly strains are used as examples to indicate the problems encountered in developing and using such strains. Furthermore, the strategies used to solve these problems are described.